Apparatus and method for x-ray imaging of breast

ABSTRACT

An apparatus for imaging a breast using an X-ray includes a support having a through-hole, a holder having a cylindrical shape, disposed in the through-hole of the support, and accommodating a breast of a patient, a linear X-ray generator disposed outside the holder and emitting an X-ray having a linear beam section that is lengthy in a vertical direction of the holder, a linear X-ray detector arranged outside the holder, and a rotation driver rotating the linear X-ray generator and the linear X-ray detector along an outer circumference of the holder.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2013-0074058, filed on Jun. 26, 2013, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

1. Field

Apparatuses and methods consistent with exemplary embodiments relate toimaging a breast using an X-ray, and more particularly, to imaging abreast using an X-ray while the breast is not pressed.

2. Description of the Related Art

A related art X-ray apparatus images the breast as follows: a patient'sbreast is placed on a support and compressed by a compression paddle toa maximum degree, an image area of a compressed breast is captured, anda captured X-ray image is output through an image processor.

To reduce an X-ray dose and obtain a superior image, the breast of apatient is compressed with a great force so that the breast issubstantially flattened out and the thickness of the breast issubstantially decreased. Further, an arm of the patient is placed higherthan a shoulder level in uncomfortable and painful position, to notobstruct the view. As a result, a patient usually feels much pain and/ordiscomfort during the breast mammography. Also, since the related artX-ray breast mammography is routinely performed at least four times toobtain a left mediolateral oblique (LMLO) view, a right mediolateraloblique (RMLO) view, a left craniocaudal (LCC) view, and a rightcraniocaudal (RCC) view, X-ray is performed for a long time so that anamount of the pain of a patient increases and the patient's radiationdose increases. Furthermore, when there are abnormality findings in animage, enlargement imaging and tomography may be additionally performed,which increases the pain and the radiation dose of a patient. Also, aworkflow may be increased.

SUMMARY

Exemplary embodiments may address at least the above problems and/ordisadvantages and other disadvantages not described above. The exemplaryembodiments are not required to overcome the disadvantages describedabove, and may not overcome any of the problems described above.

One or more exemplary embodiments include an apparatus and method forimaging a breast using an X-ray which may perform a 2D imagingcorresponding to a left mediolateral oblique (LMLO) view, a rightmediolateral oblique (RMLO) view, a left craniocaudal (LCC) view, and aright craniocaudal (RCC) view and also tomosynthesis imaging in oneoperation without compressing a patient's breast so that patient's painmay be minimized or eliminated and a workflow may be simplified.

According to one or more exemplary embodiments, an apparatus for imaginga breast image using an X-ray includes a support having a through-hole,a holder having a cylindrical shape, disposed in the through-hole of thesupport, and accommodating a breast of a patient entering through thethrough-hole, a linear X-ray generator disposed outside the holder andemitting an X-ray having a linear beam section that is lengthy in avertical direction of the holder, a linear X-ray detector arrangedoutside the holder, and a rotation driver rotating the linear X-raygenerator and the linear X-ray detector along an outer circumference ofthe holder.

The linear X-ray generator may include a plurality of X-ray generationunits that are linearly arranged.

The plurality of X-ray generation units may be cold-cathode X-raysources.

The linear X-ray detector may include a plurality of X-ray detectionunits that are arranged linearly or in a plurality of rows.

The rotation driver may rotate the linear X-ray generator and the linearX-ray detector simultaneously or selectively along an outercircumference of the holder.

The linear X-ray generator and the linear X-ray detector may rotatewhile facing each other with respect to a center axis of the holder.

The support may be a table where a patient lies.

A diameter of the through-hole may be larger than or equal to an outerdiameter of the holder.

The through-hole may include first and second through-holes.

The holder may include first and second holders respectively provided inthe first and second through-holes.

The first and second holders may be respectively provided in the firstand second through-holes of the support with an adjustable intervalbetween the first and second holders.

The apparatus may further include an interval adjustment controller thatadjusts a distance between the first and second holders.

The holder may be provided in any one of the first and secondthrough-holes.

The holder may be movably provided in the through-hole of the support.

A contact sensor for sensing a regular position of a breast of a patiententering the holder may be provided on an inner surface of the holder.

The contact sensor may be a contact pressure sensor.

The apparatus may further include a breast fixing apparatus that fixesthe breast of a patient entering the holder.

The breast fixing apparatus may be an air tube that is provided along aninner circumferential surface of the holder.

The breast fixing apparatus may be a vacuum pump that sucks internal airof the holder.

According to one or more exemplary embodiments, a method of imaging abreast using an X-ray includes fixing a breast of a patient on a holder,performing X-ray imaging while rotating a linear X-ray generator and alinear X-ray detector along outer circumference of the holder,converting an X-ray detected by the linear X-ray detector into a digitalsignal and transmitting the digital signal to an image data generator,and processing the digital signal transmitted by the image datagenerator and configuring an X-ray image.

The performing of X-ray imaging may include emitting a linear X-ray fromthe linear X-ray generator while rotating the linear X-ray generatoraround the holder, and performing X-ray imaging while rotating thelinear X-ray detector around the holder.

The linear X-ray generator and the linear X-ray detector may rotatewhile facing each other with respect to a center axis of the holder.

The rotation driver may rotate the linear X-ray generator and the linearX-ray detector simultaneously or selectively along an outercircumference of the holder.

Two holders may be provided corresponding to both breasts of a patient,the linear X-ray generator and the linear X-ray detector may be arrangedat each of the two holders, and both breasts of a patient may besimultaneously imaged using an X-ray.

The method may further include adjusting a distance between the twoholders.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will become more apparent by describingcertain exemplary embodiments with reference to the accompanyingdrawings, in which:

FIG. 1 is a schematic perspective view of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 2 is a schematic perspective view of a holder assembly employed inthe X-ray imaging apparatus of FIG. 1;

FIG. 3 is a side view of the holder assembly of FIG. 2;

FIG. 4 illustrates an example of a linear X-ray generator employed inthe holder assembly of FIG. 2;

FIGS. 5A, 5B, 5C, and 5D schematically illustrate X-ray generation unitsaccording to exemplary embodiments;

FIG. 6 illustrates an electron emission device including a gateelectrode, according to an exemplary embodiment;

FIGS. 7A, 7B, 7C, 7D, 7E, 7F, and 7G illustrate anode electrodes havingirregular thicknesses, according to exemplary embodiments;

FIG. 8 illustrates an anode electrode having a uniform thickness,according to an exemplary embodiment;

FIGS. 9A and 9B illustrate an anode electrode formed of differentmaterials, according to an exemplary embodiment;

FIGS. 10A, 10B, 10C, and 10D illustrate anode electrodes formed ofdifferent materials, according to exemplary embodiments;

FIGS. 11A, 11B, and 11C illustrate an X-ray generator generating anX-ray of a short wavelength or an X-ray of a plurality of wavelengthbands according to exemplary embodiments;

FIGS. 12A and 12B schematically illustrate X-ray detectors that may beapplied to the X-ray detector of FIG. 1;

FIGS. 13A and 13B schematically illustrate examples of an X-raydetection unit that may be applied to the X-ray detector of FIG. 1;

FIG. 14 illustrates an operation of the holder assembly of FIG. 2;

FIG. 15 is a block diagram of the X-ray imaging apparatus of FIG. 1;

FIG. 16 is a flowchart of a method of operating an X-ray imagingapparatus, according to an exemplary embodiment;

FIG. 17 is a schematic block diagram of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 18 is a schematic block diagram of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 19 illustrates an example of an arrangement of contact sensors thatare provided on a cylindrical holder assembly of the X-ray imagingapparatus of FIG. 18;

FIG. 20 illustrates a holder assembly according to an exemplaryembodiment;

FIG. 21 illustrates an operation of the holder assembly of FIG. 20;

FIG. 22 is a flowchart of a method of operating an X-ray imagingapparatus employing the holder assembly of FIG. 20;

FIG. 23 illustrates a holder assembly according to an exemplaryembodiment;

FIG. 24 is a schematic perspective view of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 25 is a schematic block diagram of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 26 illustrates a radiation field detector that is provided on aholder assembly of the X-ray imaging apparatus of FIG. 25;

FIG. 27 illustrates an operation of the radiation field detector of FIG.25;

FIG. 28 illustrates an operation of the radiation field detector of FIG.25;

FIG. 29 is a flowchart of an operation of the X-ray imaging apparatus ofFIG. 24;

FIG. 30 illustrates an arrangement of light-emitting elements of alight-emitting unit and light-receiving elements of a light-receivingunit according to an exemplary embodiment;

FIG. 31 illustrates a schematic structure of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIG. 32 schematically illustrates a cylindrical X-ray generator assemblyemployed in the X-ray imaging apparatus of FIG. 31;

FIG. 33 illustrates an example of a switch circuit used in thecylindrical X-ray generator assembly of FIG. 32;

FIG. 34 illustrates an operation of the X-ray imaging apparatus of FIG.31;

FIG. 35 is a schematic block diagram of the X-ray imaging apparatus ofFIG. 31;

FIG. 36 illustrates a radiation field detector employed in an X-rayimaging apparatus according to an exemplary embodiment; and

FIG. 37 illustrates a schematic structure of an X-ray imaging apparatusaccording to an exemplary embodiment.

DETAILED DESCRIPTION

Certain exemplary embodiments are described in greater detail below withreference to the accompanying drawings.

In the following description, like drawing reference numerals are usedfor the like elements, even in different drawings. The matters definedin the description, such as detailed construction and elements, areprovided to assist in a comprehensive understanding of exemplaryembodiments. However, exemplary embodiments can be practiced withoutthose specifically defined matters. Also, well-known functions orconstructions are not described in detail since they would obscure theapplication with unnecessary detail.

When a part may “include” a certain element, unless specified otherwise,it may not be construed to exclude another element but may be construedto further include other elements. The terms such as “˜ portion”, “˜unit”, and “˜ module”, stated in the specification may signify a unit toprocess at least one function or operation and the unit may be embodiedby hardware, software, or a combination of hardware and software.

An image may signify multi-dimensional data formed of discrete imageelements, for example, pixels in a two-dimensional (2D) image and voxelsin a three-dimensional (3D) image. For example, an image may include anX-ray image, a computed tomography (CT) image, a magnetic resonanceimaging (MRI) image, an ultrasound image, and any medical image of anobject that is acquired by other medical imaging apparatus.

An object may include a human, an animal, or a part of a human or ananimal. For example, an object may include organs such as the liver, theheart, the womb, the brain, a breast, the abdomen, etc., or bloodvessels. Also, an object may include a phantom that signifies matterhaving a volume that is approximately the intensity and effective atomicnumber of a living thing, and may include a sphere phantom having aproperty similar to a human body.

A user may be a medical doctor, a nurse, a clinical pathologist, amedical imaging expert, a technician who fixes a medical apparatus,etc., but an exemplary embodiment is not limited thereto.

Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list.

FIG. 1 is a schematic perspective view of an X-ray imaging apparatus 100according to an exemplary embodiment. Referring to FIG. 1, the X-rayimaging apparatus 100 may include a main assembly 110 and a controlapparatus 190 for controlling X-ray imaging and processing an X-rayimage. In the X-ray imaging apparatus 100, a user may manipulate thecontrol apparatus 190 and display a generated X-ray image on a console199 that is externally provided. Although FIG. 1 illustrates that thecontrol apparatus 190 is separate from the main assembly 110 andconnected thereto in a wired manner, an exemplary embodiment is notlimited thereto. In another exemplary embodiment, the control apparatus190 may be integrally formed with the main assembly 110. Also, someelements of the control apparatus 190 may be embodied by an externaldevice capable of communicating in a wireless manner.

The main assembly 110 includes a table 120 for a patient, a support 130supporting the table 120, and a holder assembly 140. Two through-holes125, where both breasts may be disposed when a patient lies on herstomach on the table 120, are formed in the table 120. One holderassembly 140 is provided in each of the through-holes 125. The holderassembly 140 is where either breast, i.e., the object, is placed andwhere X-ray imaging is performed.

The diameter of each of the through-holes 125 of the table 120 is equalto or greater than the outer diameter of the holder assembly 140 so thatthe holder assembly 140 may move within a corresponding one of thethrough-holes 125. For example, the holder assembly 140 may bedetachably coupled to an upper plate of the table 120. Since theposition or size of the object varies according to individual patients,the position of the holder assembly 140 is set to be optimal to apatient so that the patient may experience X-ray imaging at acomfortable posture. It is unnecessary to provide both holder assemblies140 to be capable of moving with respect to the table 120. For example,while only one holder assembly 140 may be provided to be capable ofmoving with respect to the table 120, the other holder assembly 140 maybe fixedly provided on the table 120.

FIG. 2 is a schematic perspective view of the holder assembly 140employed in the X-ray imaging apparatus 100 of FIG. 1. FIG. 3 is a sideview of the holder assembly 140 of FIG. 2. In FIG. 2, a rotation driver170 is omitted for convenience of explanation.

Referring to FIGS. 2 and 3, the holder assembly 140 includes a holder145, a linear X-ray generator 150 and a linear X-ray detector 160arranged outside the holder 145, and the rotation driver 170 thatrotationally drives the linear X-ray generator 150 and the linear X-raydetector 160. The holder 145 accommodates the object and may have acylindrical shape. The holder 145 may be formed of a material, such asresin, having transmissivity to an X-ray. An end portion, that is, a topend portion, of the holder 145, which is close to the table 120, may beprocessed to be smooth or formed of a soft material so that useconvenience may be improved.

The linear X-ray generator 150 and the linear X-ray detector 160 areseparately arranged on an outer surface of the holder 145 by a distance,e.g., facing each other with the holder 145 interposed therebetween.

The linear X-ray generator 150 may detect an X-ray image with a lowerradiation dose, as compared to the related art, because the linear X-raygenerator 150 is located closer to the object. In an exemplaryembodiment, a cold-emission cathode type X-ray source is employed as anX-ray generation unit 300 of the linear X-ray generator 150, and, thus,the linear X-ray generator 150 may be made compact to be arranged closeto an outer surface of the holder 145. Accordingly, an X-ray radiationdose required on the linear X-ray generator 150 may be reduced bydecreasing a distance between the linear X-ray generator 150 and theobject. For example, the linear X-ray generator 150 may be arrangedwithin about 10 cm or less, for example, only within about a fewcentimeters from the outer surface of the holder 145, and, thus, thegreatest distance between the linear X-ray generator 150 and the objectmay be within about 10 cm.

Also, since the linear X-ray generator 150 and the linear X-ray detector160 are each arranged close to the outer surface of the holder 145, anX-ray radiated by the linear X-ray generator 150 may pass through theobject and may be detected in a state of having reduced scattering.Since the X-ray is prevented from being radiated to an area other thanthe object, an amount of overall X-ray radiation may be reduced.

The two holder assemblies 140 are arranged close to each other to matchthe positions of the breasts. A distance between the two holderassemblies 140 may be a factor limiting the sizes of the linear X-raygenerator 150 and the linear X-ray detector 160 that rotate along thecircumference of the holder 145. In an exemplary embodiment, since acold-emission cathode type X-ray source is employed as the X-raygeneration unit 300 of the linear X-ray generator 150, as describedlater, the linear X-ray generator 150 is made compact and thus the twoholder assemblies 140 may be arranged close to each other to match thepositions of the breasts.

The linear X-ray generator 150 and the linear X-ray detector 160 may berotationally driven by the rotation driver 170 by 360° or other anglealong the outer circumference of the holder 145. The rotation driver 170includes a drive motor 171 provided under the holder 145 and a powertransfer unit 175 that transfers a driving force of the drive motor 171to the linear X-ray generator 150 and the linear X-ray detector 160. Thepower transfer unit 175 may have an arm structure having a centerportion coupled to a rotation shaft 172 of the drive motor 171 andbranching in opposite directions to support the linear X-ray generator150 and the linear X-ray detector 160. When the rotation shaft 172 ofthe drive motor 171 rotates, an arm of the power transfer unit 175rotates and thus the linear X-ray generator 150 and the linear X-raydetector 160 rotate along the outer circumference of the holder 145.Although FIG. 3 illustrates that the drive motor 171 is provided underthe holder 145, an exemplary embodiment is not limited thereto. Inanother exemplary embodiment, an additional power transfer shaft may beprovided between the rotation shaft 172 of the drive motor 171 and thearm of the power transfer unit 175, and the drive motor 171 may bearranged with a greater degree of freedom.

Although the linear X-ray generator 150 and the linear X-ray detector160 may be rotationally driven together by one rotation driver 170, asillustrated in FIG. 3, an exemplary embodiment is not limited thereto.In another exemplary embodiment, a rotation driver may be separatelyprovided in each of the linear X-ray generator 150 and the linear X-raydetector 160 so that the linear X-ray generator 150 and the linear X-raydetector 160 may be independently and/or selectively driven. In otherwords, X-ray imaging may be performed in a state in which, while any oneof the linear X-ray generator 150 and the linear X-ray detector 160 isfixed, the other one is rotated. For example, while the linear X-raygenerator 150 that rotates along the outer circumference of the holder145 radiates an X-ray, the linear X-ray generator 150 in a fixed statedetects the X-ray so that a set of X-ray image data is obtained. Then,the linear X-ray detector 160 is rotated by an angle and the aboveprocess of obtaining another set of X-ray image data is repeated,thereby obtaining a tomography image.

FIG. 4 illustrates an example of the linear X-ray generator 150. Asillustrated in FIG. 4, the linear X-ray generator 150 may include aplurality of the X-ray generation units 300 arranged in one dimension,i.e., as a 1D array. Each of the X-ray generation units 300 may be acold-emission cathode type X-ray source.

Each of the X-ray generation units 300 may be independently driven togenerate an X-ray. Accordingly, all of the X-ray generation units 300may be driven to radiate an X-ray to the object or some of the X-raygeneration units 300 are driven to radiate an X-ray. Also, at least twoof the X-ray generation units 300 may be simultaneously or sequentiallydriven with one or more of other ones of the X-ray generation units.When the X-ray generation units 300 are sequentially driven or partiallydriven, only some X-ray detection units 1010 of FIG. 12A or 12Bcorresponding to the X-ray generation units 300 may be driven.

Although FIG. 4 illustrates that the X-ray generation units 300 areformed on a single substrate 151, an exemplary embodiment is not limitedthereto. In another exemplary embodiment, each of the X-ray generationunits 300 is separately manufactured and the X-ray generation units 300are assembled into the linear X-ray generator 150. Alternatively, someof the X-ray generation units 300 are formed on a single substrate andthen assembled together with other X-ray generation units 300 formed onother substrates. Although it is not illustrated in FIG. 4, an X-raycontroller for controlling a proceeding path of an X-ray generated byeach of the X-ray generation units 300 not to interfere with aneighboring X-ray may be provided. In the X-ray controller, an openingis formed in an area corresponding to each of the X-ray generation units300 and an X-ray absorbing material may be formed in a grid type in theother area, for example, a boundary area between the neighboring X-raygeneration units 300.

FIGS. 5A to 5D schematically illustrate X-ray generation units 300 a,300 b, 300 c, and 300 d according to exemplary embodiments. Asillustrated in FIG. 5A, the X-ray generation unit 300 a may include anelectron emission device 310 a that emits electrons and an anodeelectrode 320 a that emits an X-ray by collision of the emittedelectrons. The anode electrode 320 a may include metal or a metal alloysuch as W, Mo, Ag, Cr, Fe, Co, Cu, etc.

The electron emission device 310 a may include a cathode electrode 312and an electron emission source 314 arranged on the cathode electrode312 and that emits electrons. The cathode electrode 312 may be metalsuch as Ti, Pt, Ru, Au, Ag, Mo, Al, W, or Cu, or a metal oxide such asindium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide(IZO), tin oxide (SnO₂), or indium oxide (In₂O₃). The electron emissionsource 314 may be formed of a material capable of emitting electrons.For example, the electron emission source 314 may be formed of metal,silicon, an oxide, diamond, diamond like carbon (DLC), a carbidecompound, a nitrogen compound, carbon nanotube, carbon nanofiber, etc.The electron emission device 310 a is an example of the cold-emissioncathode type X-ray source.

The cathode electrode 312 applies a voltage to the electron emissionsource 314. When a voltage difference occurs between the electronemission source 314 and the anode electrode 320 a, that is, the cathodeelectrode 312 and the anode electrode 320 a, the electron emissionsource 314 emits electrons and the electrons collide with the anodeelectrode 320 a. Accordingly, the anode electrode 320 a radiates anX-ray due to the collision of electrodes.

As illustrated in FIG. 5B, an electron emission device 310 b of theX-ray generation unit 300 b may further include a gate electrode 316between the electron emission source 314 and the anode electrode 320 a.The gate electrode 316 may be formed of the same material as the cathodeelectrode 312. The electron emission source 314 may emit electrons bythe voltage difference between the gate electrode 316 and the cathodeelectrode 312. As the gate electrode 316 is arranged between the cathodeelectrode 312 and the anode electrode 320 a, the electrons induced bythe electron emission source 314 by the voltage applied to the gateelectrode 316 may be controlled. Accordingly, the X-ray generation unit300 b may more stably control the emission of electrons.

As illustrated in FIG. 5C, an electron emission device 310 c of theX-ray generation unit 300 c may further include a focusing electrode 318between the electron emission source 314 and an anode electrode 320 b.The focusing electrode 318 may be formed of the same material as thecathode electrode 312. The focusing electrode 318 focuses the electronsemitted from the electron emission source 314 on an area of the anodeelectrode 320 b so as to collide therewith. The focusing electrode 318may increase X-ray generation efficiency. A voltage applied to thefocusing electrode 318 may be the same as or similar to the voltageapplied to the gate electrode 316 so that an optimal focusingperformance may be maintained.

As illustrated in FIG. 5D, an electron emission device 310 d of theX-ray generation unit 300 d may include the cathode electrode 312, theelectron emission source 314 that is arranged on the cathode electrode312 and emits electrons, the gate electrode 316 arranged separately fromthe cathode electrode 312, and the focusing electrode 318 focusing theemitted electrons.

FIG. 6 illustrates an electron emission device 400 including a gateelectrode 420, according to an exemplary embodiment. As illustrated inFIG. 6, the electron emission device 400 may include a cathode electrode410, the gate electrode 420 having a mesh structure arranged separatelyfrom the cathode electrode 410, and a plurality of insulation layers 430and a plurality of electron emission sources 440 extending in a firstdirection between the cathode electrode 410 and the gate electrode 420and arranged separately from each other in a second direction that isperpendicular to the first direction. A substrate 450 for supporting theelectron emission device 400 may be formed of an insulation materialsuch as glass. The substrate 450 may support a single electron emissiondevice 400 or a plurality of electron emission devices.

The cathode electrode 410 and the gate electrode 420 may be formed of aconductive material. The cathode electrode 410 may apply a voltage toeach of the electron emission sources 440 and may have a flat panelshape. When the cathode electrode 410 has a flat panel shape, thesubstrate 450 may be omitted. The gate electrode 420 may have a meshstructure including a plurality of openings H. For example, the gateelectrode 420 may include a plurality of gate lines 422 separately fromeach other arranged on the insulation layers 430 and a plurality of gatebridges 424 connecting the gate lines 422. Accordingly, the twoneighboring gate lines 422 and the two neighboring gate bridges 424 formone opening H.

The opening H may be arranged to expose at least a part of the electronemission sources 440 between the insulation layers 430. Since the gateelectrode 420 has a mesh structure, a large electron emission device 400may be manufactured. Although FIG. 6 illustrates that the openings H ofthe gate electrode 420 are each rectangular, an exemplary embodiment isnot limited thereto. In another embodiments, the shape of each opening Hmay be one of a circle, an oval, and a polygon. The sizes of theopenings H may be identical or different.

The insulation layers 430 are arranged between the cathode electrode 410and the gate electrode 420 and prevent electrical connection between thecathode electrode 410 and the gate electrode 420. Also, the insulationlayers 430 are arranged in multiple numbers and at least threeinsulation layers 430 may be provided. The insulation layers 430 mayhave a linear shape. The insulation layers 430 extend in one directionand are separate from one another in another direction and support thegate electrode 420. The insulation layers 430 may each include a firstinsulation layer 432 supporting an edge area of the gate electrode 420and a second insulation layer 434 supporting a middle area of the gateelectrode 420.

The insulation layers 430 may be formed of an insulation material usedfor a semiconductor device. For example, the insulation layers 430 maybe formed of at least one high-K material, as for example, hafnium oxide(HfO₂), aluminum oxide (Al₂O₃), and/or silicon nitride (Si₃N₄), whichare high-K materials having a higher dielectric rate than, for example,silicon dioxide (SiO₂).

Although FIG. 6 illustrates that the insulation layers 430 have a linearshape, an exemplary embodiment is not limited thereto. The insulationlayers 430 may have a different shape that prevents the electricalconnection between the cathode electrode 410 and the gate electrode 420and supports the gate electrode 420. For example, the second insulationlayer 434 may have a column shape and may be arranged under the gatelines 422.

The electron emission sources 440 emit electrons by the voltage appliedto the cathode electrode 410 and the gate electrode 420. The electronemission sources 440 may be alternately arranged between the insulationlayers 430. For example, the electron emission sources 440 may bearranged separately from one another with the second insulation layer434 interposed between the neighboring electron emission sources 440.The electron emission sources 440 may have a shape of strips extendingin the first direction, like the second insulation layer 434.

The gate electrode 420 is arranged above the electron emission sources440 which may be arranged separately from the gate electrode 420 toprevent the electron emission sources 440 and the gate electrode 420from being short-circuited.

The electron emission sources 440 may be formed of a material capable ofemitting electrons. As an area occupied by the electron emission sources440 in the electron emission device 400 increases, the electron emissiondevice 400 may emit a large amount of electrons. However, the electronemission device 400 may endure an electrostatic force due to adifference in the voltages applied between the electron emission sources440 and the gate electrode 420. To prevent this problem, the insulationlayers 430 and the electron emission sources 440 of an exemplaryembodiment are alternately arranged, and the gate electrode 420 havingthe opening H is arranged over an area where each of the electronemission sources 440 is arranged, thereby embodying the electronemission device 400.

Since the gate electrode 420 includes the gate bridges 424 arranged in adirection crossing the lengthwise direction of the electron emissionsources 440, a uniform electric field may be formed on surfaces of theelectron emission sources 440.

Although FIG. 6 illustrates that the electron emission sources 440 areformed in strips, an exemplary embodiment is not limited thereto. Theelectron emission sources 440 may be formed as a point type in an areacorresponding to the opening H above the cathode electrode 410. Thepoint-type electron emission sources 440 may be arranged in a 2D array,that is, in a matrix format.

Also, although FIG. 6 illustrates that the electron emission sources 440are arranged in the single electron emission device 400, an exemplaryembodiment is not limited thereto. Also, only one electron emissionsource may be arranged in the electron emission device 400 or two ormore electron emission sources may be arranged therein.

A proceeding path of the X-ray may be controlled by the shape of ananode electrode. In detail, as the thickness of the anode electrode isprovided to be irregular, the proceeding path of the X-ray radiated fromthe anode electrode may be controlled.

FIGS. 7A, 7B, 7C, 7D, 7E, 7F, and 7G illustrate anode electrodes havingirregular thicknesses according to exemplary embodiments. The anodeelectrode illustrated in each of FIGS. 7A to 7G corresponds to thesingle linear X-ray generator 150. However, an exemplary embodiment isnot limited thereto. One anode electrode may correspond to one electronemission device. For convenience of explanation, one anode electrodecorresponding to the single linear X-ray generator 150 will be describedbelow.

As illustrated in FIGS. 7A to 7G, the anode electrode may besymmetrically provided about a center axis Z of each linear X-raygenerator 150 so that an X-ray may be symmetrically radiated. Thethicknesses of anode electrodes 510 and 520 gradually decrease from thecenter axis Z of the linear X-ray generator 150 toward edges thereof, asillustrated in FIGS. 7A and 7B, and X-rays radiated from the anodeelectrodes 510 and 520 may progress to be focused at the center axis Zof the linear X-ray generator 150. The linear X-ray generator 150 mayefficiently radiate an X-ray in a partial area of the object.

In detail, surfaces 512 and 522 of the anode electrodes 510 and 520, onwhich electrons are incident, may be flat surfaces, whereas surfaces 514and 524 from which X-rays exit may be protruding surfaces with respectto the flat surfaces 512 and 522. The surfaces 514 and 524 from whichX-rays exit may be convexly curved surfaces or convex surfaces obtainedby combining flat surfaces. A position where the X-ray is focused may bedetermined by an angle θ1 and a radius R of the corresponding convexstructures. Although in FIGS. 7A and 7B the surfaces 512 and 522 of theanode electrodes 510 and 520 on which electrons are incident are flatand the surfaces 514 and 524 from which X-rays exit are protruding, anexemplary embodiment is not limited thereto. That is, the surfaces onwhich electrons are incident may be convex, whereas the surfaces fromwhich X-rays exit may be flat.

Thicknesses of anode electrodes 530 and 540 gradually increase from thecenter axis Z of the linear X-ray generator 150 toward edges thereof, asillustrated in FIGS. 7C and 7D and the X-ray radiated from each of theanode electrodes 530 and 540 may progress toward an area larger than anX-ray emitting area of each of the anode electrodes 530 and 540.Accordingly, the linear X-ray generator 150 may radiate an X-ray to anobject having a relatively large area.

In detail, surfaces 532 and 542 of the anode electrode 530 and 540, onwhich electrons are incident, may be flat surfaces, whereas surfaces 534and 544 from which X-rays exit may be concave surfaces with respect toflat surfaces 532 and 542. The surfaces 534 and 544 from which X-raysexit may be concavely curved surfaces or concave surfaces obtained bycombining flat surfaces. A size of an area where the X-ray is radiatedmay be determined by an angle θ2 and a radius R of corresponding concavestructures. Although in FIGS. 7C and 7D the surfaces 532 and 542 of theanode electrodes 530 and 540 on which electrons are incident are flatand the surfaces 534 and 544 from which X-rays exit are concave, anexemplary embodiment is not limited thereto. That is, the surfaces onwhich electrons are incident may be concave, whereas the surfaces fromwhich X-rays exit may be flat.

As illustrated in FIG. 7E, both surfaces 552, 554 of an anode electrode550 on which electrons are incident and from which X-rays exit may beconvex with respect to one another. In this case, a focal distance of anX-ray may become shorter. As another example, both surfaces on whichelectrons are incident and from which X-rays exit may be concave withrespect to one another. Alternatively, while one of the surfaces onwhich electrons are incident and from which X-rays exit may be concave,the other surface may be convex.

The thickness of an anode electrode may be partially irregular. Forexample, as it is illustrated in FIGS. 7F and 7G, anode electrodes 560and 570 may have a shape in which only some portions are convex withrespect to bottom flat surfaces 562, 572. A convex structure 566 may beidentical to other convex structures or a convex structure 576 may bedifferent from other convex structures according to an area. Thethicknesses of the convex structures 576 may be symmetrical with respectto the center axis Z of the linear X-ray generator 150. Although FIGS.7F and 7G illustrate only a convex structure, an exemplary embodiment isnot limited thereto. The anode electrode may include a concave structureor both a concave structure and a convex structure.

As such, since the progress path of an X-ray may be controlled by usingthe anode electrode having an irregular thickness, the linear X-raygenerator 150 may efficiently radiate an X-ray to the object and mayalso reduce an X-ray radiation dose.

The X-ray imaging apparatus according to an exemplary embodiment may usean anode electrode having a uniform thickness. FIG. 8 illustrates ananode electrode 580 having a uniform thickness, according to anexemplary embodiment. Referring to FIG. 8, while the anode electrode 580having a uniform thickness is used, the progress path of an X-ray may becontrolled by using a separate element such as a collimator (not shown).

The anode electrode may include a plurality of layers formed ofdifferent materials and capable of radiating X-rays of differentwavelengths. FIGS. 9A and 9B illustrate an anode electrode 710 formed ofdifferent materials, according to an exemplary embodiment. As it isillustrated in FIG. 9, the anode electrode 710 may include a pluralityof layers 711, 712, 713, and 714 formed of different materials. Thelayers 711, 712, 713, and 714 may be parallelly arranged with respect toan electron emission device. The anode electrode 710 may radiate X-raysof different wavelengths according to the layers 711, 712, 713, and 714with which electrons collide.

An anode electrode radiating X-rays of multiple wavelengths may have anon-uniform thickness as described above. FIGS. 10A, 10B, 10C, and 10Dillustrate anode electrodes 810 and 820 formed of different materials,according to exemplary embodiments. Each of the anode electrodes 810 and820 may include a plurality of layers formed of different materials andat least one of the layers may have an irregular thickness.

For example, as illustrated in FIGS. 10A and 10B, the anode electrode810 may include a plurality of layers 811, 812, 813, and 814 that areformed of different materials. The layers 811, 812, 813, and 814 havethicknesses that gradually decrease from the center axis Z of the linearX-ray generator 150 toward edges thereof. Accordingly, the anodeelectrode 810 may focus the radiated X-rays. Since the X-rays havingdifferent wavelengths are focused on different areas, a single linearX-ray generator may image many different areas having different depthsof the object at one time.

As illustrated in FIGS. 10C and 10D, the anode electrode 820 may includea plurality of layers 821, 822, and 823 that are formed of differentmaterials. The anode electrode 820 may have a change in the thicknessthereof according to the layers 821, 822, and 823. For example, thefirst layer 821 may have a thickness that gradually decreases from thecenter axis Z of the linear X-ray generator 150 toward an edge thereof,the second layer 822 may have a uniform thickness, and the third layer823 may have a thickness that gradually increases with respect to thecenter axis Z of the linear X-ray generator 150 toward the edge thereof.Accordingly, the anode electrode 820 may radiate an X-ray to a largersurrounding area while focusing on an area of interest of the object.

Also, the linear X-ray generator 150 according to an exemplaryembodiment may simultaneously or selectively generate X-rays ofdifferent wavelengths. FIGS. 11A to 11C illustrate an X-ray generatorgenerating an X-ray of a short wavelength or simultaneously generatingX-rays of a plurality of wavelength bands, according to exemplaryembodiments.

Referring to FIG. 11A, a plurality of electron emission devices 910,each having an electron emission source 912, and an anode electrode 920may be arranged separately from one another. In the anode electrode 920,first and second layers 922 and 924 that are formed of differentmaterials may be alternately arranged. When the first and second layers922 and 924 overlap with each other in an area corresponding to theelectron emission source 912 of one of the electron emission devices910, electrons emitted by the electron emission devices 910 may collidewith the first and second layers 922 and 924. Accordingly, the anodeelectrode 920 may simultaneously radiate a first X-ray X1 and a secondX-ray X2.

As illustrated in FIGS. 11B and 11C, the anode electrode 920 makes atranslational movement in parallel with the electron emission devices910 in one of a direction 930 and a direction 932. In FIG. 11B, theanode electrode 920 makes a translational movement in parallel with theelectron emission devices 910 such that the first layer 922 of the anodeelectrode 920 may be arranged to overlap or align with the electronemission source 912. The electrons emitted by the electron emissiondevices 910 collide with the first layer 922 and thus the first X-ray X1of a first wavelength may be radiated from the anode electrode 920.

As illustrated in FIG. 11C, the anode electrode 920 makes atranslational movement in parallel with the electron emission devices910 such that the second layer 924 of the anode electrode 920 may bearranged to overlap or align with the electron emission source 912. Theelectrons emitted by the electron emission devices 910 collide with thesecond layer 924 and thus the second X-ray X2 of a second wavelength maybe radiated from the anode electrode 920.

As such, since the anode electrode 920 simultaneously radiates aplurality of X-rays or selectively radiates a single X-ray, usability ofthe linear X-ray generator 150 may be improved.

As described above, the X-ray generation units 300 are arranged in thelinear X-ray generator 150. Each of the X-ray generation units 300 isseparately manufactured as one unit and then the X-ray generation units300 are assembled, thereby forming the linear X-ray generator 150. Also,a plurality of electron emission devices and an anode electrode may beintegrally manufactured on a single substrate. Alternatively, aplurality of electron emission devices are manufactured on a singlesubstrate and then an anode electrode is assembled, thereby forming alinear X-ray generator. In addition, the linear X-ray generator 150 maybe formed by a variety of methods.

The linear X-ray generator 150 may further include a collimator (notshown) for controlling a proceeding direction of an X-ray. Accordingly,an X-ray radiation dose may be reduced and also an X-ray may be moreaccurately detected.

FIGS. 12A and 12B schematically illustrate linear X-ray detectors 1000 aand 1000 b that may be used as the X-ray detector 160 of FIG. 1. Asillustrated in FIG. 12A, the linear X-ray detector 1000 a may be alinear detector having a linear detection surface in which a pluralityof X-ray detection units 1010 are arranged in one dimension.Alternatively, as illustrated in FIG. 12B, the linear X-ray detector1000 b may be a linear detector having a linear detection surface inwhich the one-dimensional arrangement of the X-ray detection units 1010is provided in two or more rows.

Each of the X-ray detection units 1010 is a light-receiving element thatreceives an X-ray and converts a received X-ray into an electric signal.For example, as illustrated in FIG. 13A, each of the X-ray detectionunits 1010 may be an indirect type X-ray receiving element including ascintillator 1011, a photodiode 1012, and a storage element 1013. Thescintillator 1011 receives an X-ray and outputs photons, in particularvisible photons, that is, a visible ray, according to a received X-ray.The photodiode 1012 receives the photons output from the scintillator1011 and converts received photons into electric signals. The storageelement 1013 is electrically connected to the photodiode 1012 and storesthe electric signal output from the photodiode 1012. The storage element1013 may be, for example, a storage capacitor. The electric signalstored in the storage element 1013 of each of the X-ray detection units1010 is applied to a signal processor (not shown) where the signal isprocessed into an X-ray image.

In another example, as illustrated in FIG. 13B, each of the X-raydetection units 1010 may be a direct type X-ray receiving elementincluding a photoconductor 1016 converting an X-ray into an electricsignal, electrodes 1015 and 1017 respectively formed on upper and lowerportions of the photoconductor 1016, and a signal processor 1018counting the electric signals transmitted from the electrode 1017 in thelower portion.

The X-ray detection units 1010 may be provided to correspond to theX-ray generation units 300 of the linear X-ray generator 150,respectively. The X-ray generation units 300 and the X-ray detectionunits 1010 may have a one-to-one correspondence. Each of the X-raygeneration units 300 may correspond to two or more X-ray detection units1010, or two or more X-ray generation units 300 may correspond to oneX-ray detection unit 1010.

The X-ray detection units 1010 may be simultaneously or independentlydriven to detect an X-ray. Accordingly, an X-ray irradiated onto theentire area of the object may be detected as all of the X-ray detectionunits 1010 are driven, or an X-ray irradiated onto a particular area ofthe object may be detected as some of the X-ray detection units 1010 aredriven. Also, at least two of the X-ray detection units 1010 may besimultaneously or sequentially driven.

Also, the X-ray detection units 1010 may be integrally formed on asignal substrate or separately manufactured and then assembled into thelinear X-ray detector 160. Next, the operation of the holder assembly140 according to an exemplary embodiment will be described below withreference to FIG. 14.

The linear X-ray generator 150 provided at one side of the holder 145radiates an X-ray having a long linear beam sectional shape toward acenter portion C of the holder 145. The linear X-ray detector 160provided at the other side with respect to the holder 145 detects theX-ray passing through the center portion C of the holder 145. Since theobject is provided in the holder 145, an X-ray signal detected by thelinear X-ray detector 160 includes image information of the object.

When the linear X-ray generator 150 and the linear X-ray detector 160perform X-ray imaging by rotating by 360° along the outer circumferenceof the holder 145, tomographic information of the object is obtained forrotational angles θ of the linear X-ray generators 150 and 160 and thustomography may be obtained based on the obtained tomographic informationand angular information. Tomographic images may be reconstructed in twoor three dimensions based on the obtained tomographic information andangular information. Also, a tomosynthesis image may be obtained. Sincean image processing algorithm to obtain a tomographic image or atomosynthesis image from the tomographic information and the angularinformation is known to those skilled in the art, a detailed descriptionthereof will be omitted.

FIG. 15 is a block diagram of the X-ray imaging apparatus 100 of FIG. 1.Referring to FIG. 15, the X-ray imaging apparatus 100 according to anexemplary embodiment includes the holder assembly 140 and the controlapparatus 190 controlling the holder assembly 140. As described above,the holder assembly 140 includes the holder 145, the linear X-raygenerator 150, the linear X-ray detector 160, and the rotation driver170 that rotationally drives the linear X-ray generator 150 and thelinear X-ray detector 160.

The control apparatus 190 may include a controller 191, an image datagenerator 192, a rotation controller 193, an X-ray driver 194, and astorage 195. The control apparatus 190 may receive an input of a commandof X-ray imaging from a user. Information about a command to drive thelinear X-ray generator 150 and the linear X-ray detector 160 of theholder assembly 140, a command to rotationally drive the linear X-raygenerator 150 of the holder assembly 140, a command to control aparameter to change a spectrum of an X-ray, etc., which are input by auser, may be transferred to the controller 191. The controller 191controls the elements in the control apparatus 190 according to theuser's command.

The image data generator 192 receives electric signals corresponding tothe X-ray detected by the linear X-ray detector 160 of the holderassembly 140. The image data generator 192 generates digital sectiondata containing information about a section of the object, from thereceived electric signals, i.e., the section data. One-time radiation ofan X-ray generates one section data containing information about asection of the object. When an X-ray is radiated many times by changingthe position of the linear X-ray generator 150, a plurality of pieces ofsection data about different sections of the object may be generated.When any pieces of neighboring section data of the generated sectiondata are accumulated, 3D volume data representing the object in threedimensions may be generated.

The rotation controller 193 controls the rotation driving of the linearX-ray generator 150 and the linear X-ray detector 160. The X-ray driver194 controls the X-ray generation units 300 of the linear X-raygenerator 150 in FIG. 4. Also, the X-ray driver 194 may control X-rayradiation intensity of the X-ray generation units 300. For example, theX-ray driver 194 may control rotation and activation of each of theX-ray generation units 300 individually or may control any number of theX-ray generation units 300 together, e.g., in groups. Also, the X-raydriver 194 may control X-ray radiation intensity of each of the X-raygeneration units 300 individually or may control radiation intensitiesof any number of the X-ray generation units 300 together, e.g., ingroups.

The storage 195 may store the section data and/or the 3D volume datagenerated by the image data generator 192. The storage 195 may transmitto the console 199 the stored section data or 3D volume data on a user'srequest.

FIG. 16 is a flowchart of a method of operating the X-ray imagingapparatus 100, according to an exemplary embodiment. Referring to FIG.16, a patient lies on her stomach on the table 120 of FIG. 1 (operationS1110). Next, the object, that is, the breast of the patient, is fixedlydisposed at the center portion C of the holder 145 (operation S1120).Next, X-ray imaging is performed by driving the holder assembly 140(operation S1130). In other words, the linear X-ray generator 150 andthe linear X-ray detector 160 are rotated by driving the rotation driver170 and then the X-ray radiation of the linear X-ray generator 150 andthe X-ray detection of the linear X-ray detector 160 are activated. TheX-ray radiation of the linear X-ray generator 150 and the X-raydetection of the linear X-ray detector 160 may be continuously ordiscontinuously performed. The rotation ranges of the linear X-raygenerator 150 and the linear X-ray detector 160 may vary according tothe purpose of imaging, for example, obtaining tomographic images ortomosynthesis images. During the X-ray imaging, an X-ray signal input tothe linear X-ray detector 160 is converted into a digital signal andthen transmitted to the image data generator 192 of FIG. 15 (operationS1140). The image data generator 192 post-processes the transmittedsignal by using an image processing algorithm and outputs an X-ray image(operation S1150).

Since the X-ray imaging apparatus 100 according to an exemplaryembodiment performs X-ray imaging when the object (the breast of apatient) is placed in the holder 145, there is no need to press theobject. In the related art mammography apparatus, X-ray imaging isperformed when the breast is pressed and thus a patient feelsdiscomfort. In contrast, the breast is not pressed during the X-rayimaging by the X-ray imaging apparatus 100 according to an exemplaryembodiment.

Further, in the X-ray imaging apparatus 100 according to an exemplaryembodiment, the imaging of a left mediolateral oblique (LMLO) view, aright mediolateral oblique (RMLO) view, a left craniocaudal (LCC) view,and a right craniocaudal (RCC) view may be completed as the linear X-raygenerator 150 and the linear X-ray detector 160 rotate once so that aworkflow may be reduced and the X-ray radiation dose to a patient may bereduced. Furthermore, since the X-ray imaging apparatus 100 according toan exemplary embodiment simultaneously images both breasts of a patientby using the two holder assemblies 140, the workflow may be furtherreduced.

Although in an exemplary embodiment a patent lies on her stomach on thetable 120, an exemplary embodiment is not limited thereto. It ispossible that the table 120 stands vertically and thus imaging isperformed while a patient stands. In this case, the table 120 may be asupport for supporting and guiding a patient.

Also, although in an exemplary embodiment the holder assembly 140 isarranged in both through-holes 125, the holder assembly 140 may bearranged in any one of the two through-holes 125.

The X-ray imaging apparatus 100 may image the entire object or a partialarea of the object in one operation. For example, when an X-raygeneration area of the linear X-ray generator 150 and an X-ray detectionarea of the linear X-ray detector 160 are equal to or larger than a testarea of the object, the linear X-ray generator 150 and the linear X-raydetector 160 may image the object by one operation. When a partial areaof the object is to be imaged, only some of the X-ray generation units300 of the linear X-ray generator 150 are operated to generate an X-rayand only some of the X-ray detection units 1010 of the linear X-raydetector 160 corresponding to the operating X-ray generation units 300may detect the X-ray.

When the an X-ray generation area of the linear X-ray generator 150 andan X-ray detection area of the linear X-ray detector 160 are smallerthan the test area of the object, at least one of the linear X-raygenerator 150 and the linear X-ray detector 160 may be driven two timesor more.

FIG. 17 is a schematic block diagram of an X-ray imaging apparatus 100according to an exemplary embodiment. The X-ray imaging apparatus 100according to an exemplary embodiment may include an interval adjuster1210 for adjusting a distance between the two holder assemblies 140.

Referring to FIG. 17, the X-ray imaging apparatus 100 includes a movableholder assembly 1241 and a fixed holder assembly 1242. The movableholder assembly 1241 and the fixed holder assembly 1242 are eachsubstantially the same as the holder assembly 140 of the X-ray imagingapparatus 100 described with reference to FIGS. 1 to 16. While themovable holder assembly 1241 is movably provided on the table 120 ofFIG. 1, the fixed holder assembly 1242 is fixed on the table 120. Theinterval adjuster 1210 may automatically move the movable holderassembly 1241 by using a driver such as an electrostatic motor, ahydraulic device, etc. The control apparatus 190 may further include aninterval adjustment controller 1290 to control driving of the intervaladjuster 1210.

Although in an exemplary embodiment the entire movable holder assembly1241 is moved by the interval adjuster 1210, an exemplary embodiment isnot limited thereto. In another exemplary embodiment, the intervaladjuster 1210 may be coupled only to the holder 145 of the movableholder assembly 1241 to move the holder 145 only. Alternatively, a powertransfer shaft may be additionally provided between the rotation shaft172 of the drive motor 171 and the power transfer unit 175 so that,while the drive motor 171 may be fixed, the other elements of themovable holder assembly 1241 may be moved by the internal adjuster 1210.

FIG. 18 is a schematic block diagram of an X-ray imaging apparatus 100according to an exemplary embodiment. FIG. 19 illustrates an example ofan arrangement of contact sensors 1312 that are provided on acylindrical holder assembly 1340, 1342 of the X-ray imaging apparatus100 of FIG. 18.

Referring to FIGS. 18 and 19, the contact sensors 1312 are arranged at aconstant interval in alignment with or on an inner circumferentialsurface 1345 a of a holder 1345. Furthermore, the contact sensors 1312may be arranged in the vicinity of an entrance of the holder 1345 and ata constant interval on the inner circumferential surface 1345 a of theholder 1345. The contact sensors 1312 detect contact of the object andare used to detect whether the object is disposed at correct positionsin the holder 1345. The contact sensors 1312 may be contact pressuresensors detecting a contact pressure of the object. The contact pressuresensor may be, for example, a sensor using a piezoelectric elementhaving an electromotive force that varies according to a contactpressure, a thin film sensor having resistance that varies according toa contact pressure, or a sensor using a microelectromechanical systems(MEMS) structure.

When the object is inserted in the holder 1345 for X-ray imaging, thecontact sensor 1312 detects contact of the inserted object. When allcontact sensors 1312 detect the contact of the object, the object isdetermined to be placed at a correct position and the X-ray imaging maybe performed. When some of the contact sensors 1312 do not detect thecontact of the object, the object may be regarded to be eccentricallyinserted to one side. Accordingly, the holder assembly 1340 is manuallyor automatically moved until all contact sensors 1312 detect the contactof the object.

When the contact sensors 1312 are contact pressure sensors, the contactsensors 1312 may detect an even contact pressure of the object. In thiscase, the object is determined to be disposed at a correct position onlywhen all contact pressures of the object detected by the contact sensors1312 are within an allowable range, and then X-ray imaging may beperformed. When the contact pressures of the object detected by some ofthe contact sensors 1312 are smaller than or larger than the allowablerange, the object is regarded to be eccentrically inserted andaccordingly, the holder assembly 1340 is manually or automatically moveduntil the contact pressures detected by all contact sensors 1312 arewithin the allowable range.

Although in an exemplary embodiment the contact sensors 1312 areprovided on both holder assemblies 1340, 1342, the contact sensors 1312may be provided only on the movable holder assembly 1340. Also, althoughin an exemplary embodiment the interval adjuster 1210 is provided, themovable holder assembly 1340 may be manually moved without using theinterval adjuster 1210.

FIG. 20 illustrates a holder assembly 1440 according to an exemplaryembodiment. FIG. 21 illustrates an operation of the holder assembly 1440of FIG. 20. An X-ray imaging apparatus according to an exemplaryembodiment may be understood as one obtained by adding a breast fixingapparatus 1450 to the X-ray imaging apparatus 100 described above.

Referring to FIGS. 20 and 21, the breast fixing apparatus 1450 may be anexpandable air tube provided on an inner circumferential surface 1445 aof a holder 145. The breast fixing apparatus 1450 may be provided in thevicinity of an entrance of the holder 145. When an object 200 isinserted in the holder 145 for X-ray imaging, the air is supplied by anair pump (not shown) to the inside of the breast fixing apparatus 1450and the breast fixing apparatus 1450 expands to occupy the space betweenthe object 200 and the inner circumferential surface 1445 a asillustrated in FIG. 21, thereby fixing the object 200.

FIG. 22 is a flowchart of a method of operating an X-ray imagingapparatus according to an exemplary embodiment. Referring to FIG. 22, amethod of fixing an object, according to an exemplary embodiment,includes placing one breast of a patient at a center portion of theholder 145 corresponding to the breast (operation S1510), adjusting adistance of the holder assembly 1440 such that the other breast of thepatient may be disposed at a center portion of the other holder 145(operation S1520), fixing the breast by injecting air into an air tubethat is the breast fixing apparatus 1450 (operation S1530), andadjusting air in the breast fixing apparatus 1450 so that a constantpressure may be applied to the object according to the size of theobject (operation S1540). The above-described breast fixing process maybe additionally added between placing the object in the holder 145(operation S1120) and performing X-ray imaging (operation S1130), whichare described above with reference to FIG. 16.

Although in the above description an expandable air tube is used as thebreast fixing apparatus 1450, an exemplary embodiment is not limitedthereto. FIG. 23 illustrates a holder assembly 1640 according to anexemplary embodiment. Referring to FIG. 23, a breast fixing apparatus1650 may be a vacuum pump connected to a lower end of a holder 145. Whenthe object is inserted in the holder 145 for X-ray imaging, the breastfixing apparatus 1650 softly sucks air from an inside area 1645 a of theholder 145 so that the object is pulled and fixed.

Although in the above-described exemplary embodiments two holderassemblies are provided, an exemplary embodiment is not limited thereto.As illustrated in FIG. 24, in an X-ray imaging apparatus 100 accordingto an exemplary embodiment, only one through-hole 1725 may be providedin a table 1720 and only one holder assembly 1740 may be provided in thetable 1720.

FIG. 25 is a schematic block diagram of an X-ray imaging apparatus 100,according to an exemplary embodiment, which includes the holder assembly1840 provided with the radiation field detector 1870. Although FIG. 25illustrates a case in which only one holder assembly 1840 is provided,two holder assemblies 1840 may be provided. FIG. 26 illustrates indetail a radiation field detector 1870 of the X-ray imaging apparatus100 of FIG. 25.

Referring to FIG. 25, the radiation field detector 1870 includes alight-emitting unit 1850, a light-receiving unit 1860, and a radiationfield setter 1890 that controls the light-emitting unit 1850 and thelight-receiving unit 1860 and sets a radiation field. As illustrated inFIG. 26, the light-emitting unit 1850 and the light-receiving unit 1860may be arranged close to the linear X-ray generator 150 and the linearX-ray detector 160, respectively.

As illustrated in FIG. 26, the light-emitting unit 1850 has a structurein which a plurality of light-emitting elements 1851 are linearlyarranged at an identical interval at one side of the linear X-raygenerator 150. The light-emitting elements 1851 may be, for example,light-emitting diodes, organic light-emitting diodes, laser diodes,lamps, etc., which emit visible rays or infrared rays. Light emittedfrom the light-emitting elements 1851 may have a linear beam sectionthat is lengthy discontinuously in the same direction as a direction inwhich the linear X-ray generation units 150 are arranged. In anotherexemplary embodiment, the light-emitting unit 1850 may have a linearlight source which elongates in a direction, thus emitting light havinga linear beam section that is lengthy continuously in the same directionas the direction in which the linear X-ray generation units 150 arearranged. A focusing lens such as a collimator lens may be additionallyprovided at a light-emitting surface of each of the light-emittingelements 1851 to allow the light rays emitted by the light-emittingelements 1851 to have a directivity. The wavelength range of the lightemitted by the light-emitting elements 1851 or the type of light sourceis not limited.

The light-receiving unit 1860 has a structure in which a plurality oflight-receiving elements 1861 are linearly arranged at an identicalinterval in a vertical direction at one side of the linear X-raydetector 160. The light-receiving elements 1861 may be photodiodes,phototransistors, or image sensors which have a detection rangecorresponding to the wavelength range of the light emitted by thelight-emitting elements 1851. The light-emitting unit 1850 and thelight-receiving unit 1860 may be respectively attached on the lateralsurfaces of the linear X-ray generator 150 and the linear X-ray detector160 at the upstream side with respect to a rotation direction 1876, asillustrated in FIG. 28. That is, the light-emitting unit 1850 and thelight-receiving unit 1860 may be respectively attached on the leadingsurfaces of the linear X-ray generator 150 and the linear X-ray detector160 in a rotation direction. In this case, the light emitted by thelight-emitting unit 1850 proceeds toward the light-receiving unit 1860after passing through a center portion of a holder 145. The arrangementsof the light-emitting unit 1850 and the light-receiving unit 1860 arenot limited thereto and thus the light-emitting unit 1850 and thelight-receiving unit 1860 may be attached on the lateral surfaces of thelinear X-ray generator 150 and the linear X-ray detector 160 at thedownstream side with respect to the rotation direction, or vice versa.

FIGS. 27 and 28 illustrate an operation of the radiation field detector1870 of FIG. 25. For convenience of explanation, the holder 145 isomitted in FIG. 27.

Referring to FIGS. 27 and 28, when the object 200 is inserted in theholder 145 for X-ray imaging, the light-emitting unit 1850 emits light Ltoward the light-receiving unit 1860 disposed opposite to thelight-emitting unit 1850. The emitted light L proceeds toward thelight-receiving unit 1860. Since the object 200 occupies a portion of aninner space of the holder 145, part of the light L does not arrive atthe light-receiving unit 1860. Accordingly, there is an imaginaryboundary 1874 between a light-receiving element 1861 a that does notreceive the light L and a light-receiving element 1861 b that adjoinsthe light-receiving element 1861 a and detects the light L among thelight-receiving elements 1861 that are vertically arranged. In otherwords, the light-receiving elements 1861 may be divided into an areathat does not receive the light L and an area that receives the light Laccording to whether the light-receiving elements 1861 receive light ornot. An optical path between the light-receiving element 1861 a that isthe last one of the light-receiving elements 1861 that are verticallyarranged and does not receive light, and a light-emitting element 1851 acorresponding to the light-receiving element 1861 a may be understood asan area where an end portion of the object 200 is located. The area 1871that does not receive the light L may be set to be an X-ray radiationfield 1871. Further, considering movements of a patient during imaging,an area including a light-receiving element 1861 b that detects thelight L and is also disposed closest to the boundary is set to beincluded into an X-ray radiation field 1871. Accordingly, only the X-raygeneration units 300 of the linear X-ray generator 150 corresponding tothe set X-ray radiation field 1871 may be activated. The outer area 1872is a non-irradiation field where an X-ray is not irradiated.

FIG. 29 is a flowchart of an operation of an X-ray imaging apparatus ofFIG. 25. Referring to FIG. 29, when the object 200 is inserted in theholder 145 and preparation of X-ray imaging is completed, thelight-emitting unit 1850 is driven to emit the light L. Thelight-receiving unit 1860 detects the light L of the light-emitting unit1850 and thus the size of the object 200 is determined (operationS1910). In operation S1920, only the X-ray generation units 300 of thelinear X-ray generator 150 that correspond to the area where the object200 is disposed are activated, so that the X-ray is radiated only to theX-ray radiation field 1871 that corresponds to the size of the object200 (operation S1930). As such, since the X-ray generation units 300corresponding to the outer area 1872 of the X-ray radiation field 1871are not driven, an X-ray radiation dose may be reduced and driving powerof the linear X-ray generator 150 may be reduced.

The determining of a radiation field may be performed before the X-rayimaging is performed. In other words, when the object 200 is inserted inthe holder 145 and the preparation of the X-ray imaging is completed,the light-emitting unit 1850 and the light-receiving unit 1860 aredriven and rotated so that the entire size of the object 200 is scannedand then X-ray imaging may be performed for only the radiation field.

In another example, the determining of the radiation field may beperformed simultaneously with the X-ray imaging. As described above, theX-ray imaging is performed while the linear X-ray generator 150 and thelinear X-ray detector 160 rotate around the holder 145. Accordingly,while the linear X-ray generator 150 and the linear X-ray detector 160rotate around the holder 145 and simultaneously the X-ray imaging isperformed, the light-emitting unit 1850 and the light-receiving unit1860 are continuously or discontinuously driven to determine the X-rayradiation field. Accordingly, an X-ray radiation range may be determinedin real time.

The above-described X-ray radiation field determination operation may beimplemented before or at the same time as performing X-ray imaging(operation S1130), in the operation of the X-ray imaging apparatusdescribed above with reference to FIG. 16.

Although the light-emitting elements 1851 and the light-receivingelements 1861 are described to be arranged at identical intervals, anexemplary embodiment is not limited thereto. FIG. 30 illustrates anarrangement of a plurality of light-emitting elements 1951 of alight-emitting unit 1950 and a plurality of light-receiving elements1961 of a light-receiving unit 1960, according to an exemplaryembodiment. As illustrated in FIG. 30, the light-emitting elements 1951and the light-receiving elements 1961 of the light-receiving unit 1960may be irregularly arranged. The size or shape of the object, that is,the breast of a patient, may be averaged. Accordingly, considering theaverage size of the object, the light-emitting elements 1951 and thelight-receiving elements 1961 corresponding thereto may be denselyarranged in the vicinity of an area where the end portion of the averageobject is placed, whereas the light-emitting elements 1951 and thelight-receiving elements 1961 corresponding thereto may be sparselyarranged in the other area. In other words, the light-receiving elements1961 disposed in the vicinity of a boundary between a light-receivingelement 1961 a that does not detect the light L and a light-receivingelement 1961 b that adjoins the light-receiving element 1961 a anddetects the light L, among the light-receiving elements 1961 that arevertically arranged, are densely arranged, whereas the light-emittingelements 1951 and the light-receiving elements 1961 are sparselyarranged. As such, according to the above arrangement of thelight-emitting elements 1951 and the light-receiving elements 1961, amore accurate size of the average object may be determined and, as thenumber of parts in use decreases, manufacturing costs may be reduced.

FIG. 31 illustrates a schematic structure of an X-ray imaging apparatus2000 according to an exemplary embodiment. FIG. 32 schematicallyillustrates a cylindrical X-ray generator assembly 2050 employed in theX-ray imaging apparatus 2000 of FIG. 31.

Referring to FIGS. 31 and 32, the X-ray imaging apparatus 2000 includesa main assembly 2010 where X-ray imaging is performed and a controlapparatus 2090 controlling the main assembly 2010. The main assembly2010 includes a housing 2020 having a cylindrical shape and thecylindrical X-ray generator assembly 2050 and a linear X-ray detector2060 which are provided in the housing 2020. The X-ray imaging apparatus2000 according to an exemplary embodiment may perform X-ray imaging onthe entire body or a particular portion of a patient (hereinafter,referred to as the object).

Referring to FIG. 32, the cylindrical X-ray generator assembly 2050 hasa structure in which a plurality of X-ray generation units 2052 aretwo-dimensionally arranged on an inner circumferential surface of acylinder. The cylindrical X-ray generator assembly 2050 may besequentially driven along a circumferential direction 2059. Thecylindrical X-ray generator assembly 2050 may be understood as astructure in which a plurality of linear X-ray generators 2051 that areindependently switched are arranged around the circumferential direction2059. Each linear X-ray generator 2051 may include the X-ray generationunits 2052 that are linearly arranged. The X-ray generation units 2052are provided to radiate all X-rays perpendicularly to thecircumferential direction 2059 toward a center axis of the cylindricalX-ray generator assembly 2050. The linear X-ray generator 2051 and theX-ray generation units 2052 may respectively correspond to the linearX-ray generator 150 and the X-ray generation units 300 that aredescribed above. A switching circuit 2053 may be individually providedfor each linear X-ray generator 2051. The switching circuit 2053 may bea circuit using a switching operation of a transistor as illustrated inFIG. 33. The switching circuit of FIG. 33 is a mere example and avariety of appropriate switching circuits may be used. When inputsignals are sequentially applied to switching circuits provided in thecircumferential direction 2059 of the cylindrical X-ray generatorassembly 2050, power is applied to a corresponding one of the linearX-ray generators 2051 and thus the linear X-ray generators 2051 aresequentially driven in the circumferential direction 2059 of thecylindrical X-ray generator assembly 2050.

The linear X-ray detector 2060 is provided to be capable of rotatingalong the circumference of the housing 2020. The linear X-ray detector2060 may be disposed inside the cylindrical X-ray generator assembly2050. The linear X-ray detector 2060 may be driven to be rotated by adevice known to those skilled in the art. Referring to FIG. 34, when thelinear X-ray generators 2051 sequentially radiate X-rays along thecircumferential direction 2059 of the cylindrical X-ray generatorassembly 2050, the linear X-ray detector 2060 rotates in a direction2069 to a position opposite to a corresponding one of the linear X-raygenerators 2051 that radiates an X-ray with respect to the center axisand detects the X-rays that are sequentially radiated. When all of thelinear X-ray generators 2051 are sequentially driven along thecircumferential direction 2059, the linear X-ray detector 2060 rotatesby 360° accordingly.

Only some of the linear X-ray generators 2051 may be sequentiallydriven. In this case, the linear X-ray detector 2060 may rotate withinan angular range corresponding thereto. In some cases, when an X-ray Xis radiated by any one of the linear X-ray generators 2051 of thecylindrical X-ray generator assembly 2050, the linear X-ray detector2060 may rotate within an angle and detect the X-ray in the vicinity ofa position opposite to the corresponding linear X-ray generators 2051.As such, since the X-ray is radiated to the object at a varying angle,an X-ray signal detected by the linear X-ray detector 2060 includesangular information and tomographic information. Accordingly, atomographic image or a tomosynthesis image may be obtained based on theobtained angular information and tomographic information. Also, atomographic image may be reconstructed in two or three dimensions basedon the obtained angular information and tomographic information.

Since only the linear X-ray detector 2060 that is relatively light ismechanically driven and rotated in the X-ray imaging apparatus 2000according to an exemplary embodiment, a relatively small load is appliedto a rotation driver 2070 of FIG. 35 and thus a mechanical structure ofthe rotation driver 2070 may be greatly simplified.

FIG. 35 is a schematic block diagram of the X-ray imaging apparatus 2000of FIG. 31. Referring to FIG. 35, the X-ray imaging apparatus 2000according to an exemplary embodiment includes a cylindrical X-raygenerator assembly 2050, a linear X-ray detector 2060, the rotationdriver 2070 driving the linear X-ray detector 2060 to rotate, and acontrol apparatus 2090 controlling the above elements.

The control apparatus 2090 may include a controller 2091, an image datagenerator 2092, a rotation controller 2093, an X-ray driver 2094, and astorage 2095. The control apparatus 2090 may receive an input of acommand about X-ray imaging from a user through a console 2099. Theinformation about a command to drive the cylindrical X-ray generatorassembly 2050, a command to activate the linear X-ray detector 2060, acommand to rotationally drive the linear X-ray detector 2060, a commandto control a parameter to change a spectrum of an X-ray, etc., which areinput by a user, is transferred to the controller 2091. The controller2091 controls the elements in the control apparatus 2090 according tothe user's command.

The image data generator 2092 receives electric signals corresponding tothe X-ray detected by the linear X-ray detector 2060. The image datagenerator 2092 generates digital sectional data containing informationabout a section of the object, from the received electric signals.One-time radiation of an X-ray by any one linear X-ray generator 2051 ofthe cylindrical X-ray generator assembly 2050 generates one sectionlinear data containing information about a section of the object.

A plurality of pieces of section data about different sections of theobject are generated when the X-ray is radiated many times by varyingthe positions of the linear X-ray generators 2051 of the cylindricalX-ray generator assembly 2050. When the pieces of section data areaccumulated into adjoining section data, 3D volume data representing theobject in three dimensions may be generated.

The rotation controller 2093 controls the rotation driver 2070 to drivethe cylindrical X-ray generator assembly 2050 to rotate. The rotationdriver 2070 includes a drive motor 2071 and a power transfer unit 2075controlling a driving force generated by the drive motor 2071 andtransferring the controlled driving force to the linear X-ray detector2060.

The X-ray driver 2094 sequentially controls the linear X-ray generators2051 of the cylindrical X-ray generator assembly 2050. Also, the X-raydriver 2094 may individually or collectively control X-ray radiationstrength of the X-ray generation units 2052 of the linear X-raygenerators 2051.

The storage 2095 may store the section data and/or the 3D volume datagenerated by the image data generator 2092. The storage 2095 maytransmit to the console 2099 the stored section data or 3D volume dataon a user's request.

FIG. 36 illustrates a radiation field detector 2160 employed in an X-rayimaging apparatus, according to an exemplary embodiment, that may beadditionally provided to the linear X-ray detector 2060 of the X-rayimaging apparatus 2000 that is described with reference to FIGS. 31 to35.

Referring to FIG. 36, the radiation field detector 2160 may extend in alengthwise direction and may be provided at one side of the linear X-raydetector 2060 which includes detection units 2061. The radiation fielddetector 2160 may include a plurality of light sensors 2161 that arelinearly arranged. The light sensors 2161 may be arranged at anidentical interval. Alternatively, the light sensors 2161 may bearranged densely in a section corresponding to an area that is aboundary of a radiation field and sparsely in the other section.

The light sensor 2161 is a light sensor detecting luminosity. Theradiation field detector 2160 may be integrally combined with the linearX-ray detector 2060 and rotate along the circumference of the housing2020 of FIG. 31 with the linear X-ray detector 2060. The linear X-raydetector 2060 and the radiation field detector 2160 may be disposed onan inner wall surface of the housing 2020. In this case, the inner wallsurface of the housing 2020 may be formed of a transparent material sothat the light sensor of the radiation field detector 2160 may detectluminosity. In some cases, the linear X-ray detector 2060 and theradiation field detector 2160 may be disposed outside the inner wallsurface of the housing 2020.

When the object is located inside the housing 2020, an area where theobject is located is different than an area where the object in terms ofluminosity detected by the radiation field detector 2160 according to adifference in the distance from the radiation field detector 2160 andshadow generated by the object. Accordingly, when the radiation fielddetector 2160 rotates along the circumference of the housing 2020 withthe linear X-ray detector 2060, approximate position and size of theobject may be detected by the radiation field detector 2160. The controlapparatus 2090 of FIG. 31 may determine an X-ray radiation field basedon the approximate position and size of the object detected by theradiation field detector 2160.

As described above, since the X-ray generation units 2052 of thecylindrical X-ray generator assembly 2050 may be individuallycontrolled, only the X-ray generation units 2052 corresponding to theX-ray radiation field are activated. Accordingly, an X-ray radiationdose to the object may be reduced and also the driving power of thecylindrical X-ray generator assembly 2050 may be reduced.

The determining of the X-ray radiation field may be performed before theX-ray imaging is performed. In other words, when the object enters thehousing 2020 and preparation of the X-ray imaging is completed, theradiation field detector 2160 is driven and rotated along thecircumference of the housing 2020 to scan the total size of the objectand then X-ray imaging is performed on a target object only.

In another case, the determining of the X-ray radiation field may beperformed at the same time with the X-ray imaging. As described above,since the X-ray imaging is performed while the linear X-ray detector2060 rotates along the circumference of the housing 2020, during theX-ray imaging, the radiation field detector 2160 is continuously ordiscontinuously driven to determine the X-ray radiation field.Accordingly, an X-ray radiation range may be determined in real time.

FIG. 37 illustrates a schematic structure of an X-ray imaging apparatus2000, according to an exemplary embodiment, which additionally includesa radiation field detector 2150.

The radiation field detector 2150 may be a sensor that is provided at anupper portion of an entrance of the housing 2020 and recognizes aparticular portion of a table 2170 or a particular portion of a patient2080 when the patient 2080 lying on the table 2170 enters the housing2020. A marker may be attached on the particular portion of the table2170 or a radiation target field of the patient 2080. The radiationfield detector 2150 may be a proximity sensor, an image sensor, etc.When the patient enters the housing 2020 by lying on the table 2170, theradiation field detector 2150 recognizes the particular portion of thetable 2170 or the particular portion of the patient. The position of thepatient may be specified by integrating an entering velocity of thetable 2170 for an entering time by using the position recognized by theradiation field detector 2150 as a reference point. When the X-rayradiation field of the patient is specified, a user may activate onlythe X-ray generation units 2052 corresponding to the X-ray radiationfield through the control apparatus 2090. Accordingly, an X-rayradiation dose to an object may be reduced and also the driving power ofthe cylindrical X-ray generator assembly 2050 may be reduced.

As described above, in the device and method for controlling an X-rayradiation field of an X-ray imaging apparatus according to one or moreof exemplary embodiments, a radiation exposure to a patient may bereduced as compared to a related art X-ray imaging apparatus. Also, animage may be rapidly obtained as compared to the related art lineardetector type X-ray imaging apparatus.

Also, when the X-ray imaging apparatus is used as a breast imagingapparatus, an operation of pressing the breast of a patient is notneeded and thus the patient is not in pain due to breast compression.Since the steps and frequencies of imaging may be remarkably reduced, ascompared to the related art imaging requiring both of general imaging ofRCC, RMLO, LCC, and LMLO and tomosynthesis imaging, a workflow may besimplified and a patient's radiation dose may be reduced.

Also, when a limited area is to be X-ray imaged, an X-ray radiationfield is manually or automatically set so that X-ray may be radiated ina particular area only by automatically controlling turning on/off of anX-ray source of the X-ray generator, thereby reducing a radiation doseto the patient. Furthermore, when the X-ray imaging apparatus is used asa breast imaging apparatus, in consideration that the sizes of a breastare different for patients, when the breast of a patient is inserted ina breast imaging apparatus, the breast size of a patient isautomatically recognized through a detection sensor attached next to theX-ray generator. The on/off of the X-ray source is automaticallycontrolled so that an X-ray may be radiated only to the recognized sizeof breast, thereby reducing radiation to the patient. Also, since theX-ray radiation field is controlled by automatically recognizing aimaging area of the breast of a patient, a imaging time may be reduced.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting. The present teaching can bereadily applied to other types of apparatuses. The description of theexemplary embodiments is intended to be illustrative, and not to limitthe scope of the claims, and many alternatives, modifications, andvariations will be apparent to those skilled in the art. For example,each single component may be separated into multiple components whichare then separately implemented. Also, separated components may becombined together and implemented as a single component.

What is claimed is:
 1. An apparatus for imaging a breast using an X-ray,the apparatus comprising: a support having a through-hole; a holderhaving a cylindrical shape, which is configured to be disposed in thethrough-hole, and accommodate the breast entering through thethrough-hole; a linear X-ray generator configured to be disposed outsideof the holder and to emit an X-ray having a linear beam section that islengthy in a vertical direction of the holder; a linear X-ray detectorconfigured to be arranged outside of the holder; and a rotation driverconfigured to rotate the linear X-ray generator and the linear X-raydetector along an outer circumference of the holder.
 2. The apparatus ofclaim 1, wherein the linear X-ray generator comprises X-ray generationunits that are linearly arranged.
 3. The apparatus of claim 2, whereinthe X-ray generation units comprise cold-cathode X-ray sources.
 4. Theapparatus of claim 1, wherein the linear X-ray detector comprises X-raydetection units that are arranged linearly or in rows.
 5. The apparatusof claim 1, wherein the rotation driver is configured to rotate thelinear X-ray generator and the linear X-ray detector simultaneously orselectively along an outer circumference of the holder.
 6. The apparatusof claim 1, wherein the linear X-ray generator and the linear X-raydetector are configured to rotate while facing each other with respectto a center axis of the holder.
 7. The apparatus of claim 1, wherein thesupport is configured to support the patient.
 8. The apparatus of claim1, wherein a diameter of the through-hole is larger than or equal to anouter diameter of the holder.
 9. The apparatus of claim 1, wherein thethrough-hole comprises first and second through-holes.
 10. The apparatusof claim 9, wherein the holder comprises first and second holdersrespectively provided in the first and second through-holes.
 11. Theapparatus of claim 10, wherein the first and second holders arerespectively provided in the first and second through-holes with anadjustable distance between the first and second holders.
 12. Theapparatus of claim 11, further comprising: an interval adjustmentcontroller that is configured to adjust the distance between the firstand second holders.
 13. The apparatus of claim 9, wherein the holder isprovided in any one of the first and second through-holes.
 14. Theapparatus of claim 1, wherein the holder is movably provided in thethrough-hole.
 15. The apparatus of claim 1, wherein a contact sensorconfigured to sense a position of the breast entering the holder isprovided on an inner surface of the holder.
 16. The apparatus of claim15, wherein the contact sensor comprises a contact pressure sensor. 17.The apparatus of claim 1, further comprising a breast fixing apparatusconfigured to fix the breast in the holder.
 18. The apparatus of claim17, wherein the breast fixing apparatus comprises an air tube that isprovided along an inner circumferential surface of the holder.
 19. Theapparatus of claim 17, wherein the breast fixing apparatus comprises avacuum pump configured to suck an internal air from the holder.
 20. Amethod of imaging a breast using an X-ray, the method comprising: fixinga breast in a holder; performing X-ray imaging while rotating a linearX-ray generator and a linear X-ray detector along an outer circumferenceof the holder; converting an X-ray detected by the linear X-ray detectorinto a digital signal; processing the digital signal; and reconstructingan X-ray image.
 21. The method of claim 20, wherein the performing theX-ray imaging comprises: emitting a linear X-ray from the linear X-raygenerator while rotating the linear X-ray generator around the holder;and performing the X-ray imaging while rotating the linear X-raydetector around the holder.
 22. The method of claim 21, furthercomprising: rotating the linear X-ray generator and the linear X-raydetector which face each other with respect to a center axis of theholder.
 23. The method of claim 20, wherein the performing the X-rayimaging comprises: rotating the linear X-ray generator and the linearX-ray detector simultaneously or selectively along the outercircumference of the holder.
 24. The method of claim 20, wherein twoholders are provided corresponding to two breasts, a respective linearX-ray generator and a respective linear X-ray detector are arranged ateach of the two holders, and the two breasts are simultaneously imaged.25. The method of claim 24, further comprising adjusting a distancebetween the two holders.
 26. An X-ray apparatus comprising: a supportconfigured to support an object and having an opening; a holderconfigured to be disposed in the opening and accommodate a breast of theobject; an X-ray generator configured to be disposed at an outer side ofthe holder and to emit an X-ray; an X-ray detector configured to bearranged at the outer side of the holder opposing the X-ray generatorand to receive the X-ray having passed through the breast; and arotation driver configured to simultaneously rotate the X-ray generatorand the X-ray detector around an outer circumference of the holder; andan image processor configured to generate an X-ray image of the breastduring one rotation of the X-ray generator and the X-ray detector. 27.The apparatus of claim 26, wherein the X-ray generator comprises X-raygeneration units that are arranged in a first array, and the X-raydetector comprises X-ray detection units that arranged in a second arrayin correspondence to the X-ray generation units.
 28. The apparatus ofclaim 27, wherein the X-ray generation units comprise cold-cathode X-raysources.
 29. The apparatus of claim 27, further comprising: an imageprocessor configured to generate an X-ray image of the breast comprisinga mediolateral oblique (RMLO) view and a craniocaudal (LCC) view duringone rotation of the X-ray generator and the X-ray detector.
 30. Theapparatus of claim 29, wherein the X-ray image of the breast isgenerated without flattening out the breast by a pressure plate.